1. Field of the Invention
The present invention relates to a keyboard switch in which the actuating part and the surrounding part thereof are substantially positioned on the same plane.
2. Description of the Prior Art
Recent technical progresses in the field of electronic parts have realized thin small keyboard switches. The actuating stroke of the keyboard switch, which conventionally was in a range of 1 to 4 mm, has been made shorter to a range of 0.1 to 0.5 mm. Such keyboard switch is surfacially covered with a flexible sheet, and the symbols representing switch functions or characters or numerals are either printed on the inner surface of said sheet or displayed by means of light-emitting diodes or liquid crystal display devices. Such keyboard switches are generally called flat keyboard switches. FIG. 1 shows the structure of a display keyboard utilizing such a flat keyboard switch in combination with a liquid crystal display device for displaying symbols corresponding to the switches.
As shown in FIG. 1, the conventional flat keyboard switch FKB is surfacially covered with a flexible glossy sheet, which may be smeared with the stain or sweat of the finger upon contact at the data input operation. Such a smear or stain often becomes noticeable to the operator when the light reflected on said sheet enters the eye of the operator, thus hindering the observation of the symbols displayed on a liquid crystal display unit DSP and giving an unpleasant feeling to the operator.